The adverse impacts of extreme climate events and physical deterioration of watersheds on sustainable management of water resources

Being the world largest tropical archipelago, Indonesia has anabundance of water with an average annual runoff per capita in the order of 17,000 m3. Nevertheless, the water resources are distributed unevenly by islands and by regions. About 60% of the 210 millions population alone [December 1999), is concentrated on the Java Island, which is continuously to become the most limiting factors of the couun­ tr's development. The rapid expansion of human settlement and in­ duustrial areas in the river basins including urbanization, conversion of agricultural lands, and illegal settlements in the vicinity of the river territories -- have also contributed apparent hurdles that are hamper­ ing the water resources development and management (WRDM] en­deavors. In the mean time, the problems of WRDM have also become aggravated, due to the inappropriate land uses, acceleration of ero­ sion, declining the water retention capacity, and eventuality of fre­ quent landslide incidents, which are hazardous to human settlement activities. The river runoff and the rainfall pattem relationship have been increasingly unpredictable -- especially with the presence of the La-Nina and El-Nino phenomenon. Having the facts that the development program and its imple.mentation during the last few years have been undertaken without adequate environmental consideration, a number of negative conse­ quences have become apparent. Therefore, a special effort is indispen­ sable for promoting the sense of crises as well as the sense of aware­ ness of the public conceming the underling predicaments of water­ shed environment. Subsequently, dissemination of knowledge and technology pertaining to sustainable utilization of water b virtue of "ecohdrological" approach is becoming eminently instrumental for re­ ducing the pressures resulted from inappropriate natural resources exploitation. In line with these matters, the Indonesia's policy and strategy in WRDM has been reformulated to an emphasis on operation and management of the water resources infrastructures based on in­ tegrated river basin management approach aiming for sustainable management of water resources as the ultimate goal. This policy re­ view is based on several major aspects namely: (l] water resources management; (2) environmental management; (3) legal and adminis­ trative aspects; and (4] socio-economics as well as finance.Given the above indications, it becomes obvious that the absence of significant attention on "ecohdrological" consideration, the adverse impacts of extreme climate events and deterioration of watershed si­ multaneoust, will become phenomenal to an WRDM program. Thispaper is about the adverse impacts of extreme climate events together with watershed deterioration resulted from human interventions. The analyses have been based upon a number of empirical evidences on flood and drought mitigation cases in Indonesia. The paper also dis­ cusses some aspects of river environment and micro-climatic trends, as well as their contributions to flood and drought incidents.